| Ecodev (Alyth) Solar Ltd | London | 2023 |
| Ecodev (South) Ltd | London | 2021 |
| Ecoflame GAS Services Ltd | Solihull | 2023 |
| Ecoflux Ltd | Glasgow | 2025 |
| Ecogen Electric Ltd | Barking | 2023 |
| Ecogreen City Energy Ltd | Glasgow | 2020 |
| Ecogreen Electrical Ltd | Billericay | 2023 |
| Ecogreenrm Limited | Saffron Walden | 2022 |
| Ecologic Group Ltd | Blackburn | 2022 |
| Ecological Energy Ltd | Exeter | 2009 |
| Ecolume Ltd | Loughborough | 2024 |
| Ecomaldon Limited | Colchester | 2024 |
| Ecomet Holdings Limited | Waltham Abbey | 2024 |
| Econditioning Limited | Ilford | 2018 |
| Econergy International Limited | London | 2020 |
| Economy Energy Trading Limited | 1 Oxford Street | 2011 |
| Economy GAS Limited | Sale | 1995 |
| Economy Power Limited | Nottingham | 1997 |
| Economy Savings Ltd | London | 2002 |
| Ecopower 2 Park Farm Ltd | London | 2022 |
| Ecopower 3 Hayton Ltd | London | 2022 |
| Ecopower 5 Exton Ltd | London | 2022 |
| Ecopower Limited | Glasgow | 1993 |
| Ecopower Suffolk Ltd | London | 2024 |
| Ecosmart Solar Ltd | London | 2025 |
| Ecosmart Solar Solutions Ltd | East Tilbury | 2026 |
| Ecosolar 1 Berrington Limited | London | 2022 |
| Ecosolar 3 Leighton Limited | London | 2022 |
| Ecosse Solar Parks Ltd | Forfar | 2019 |
| Ecossol PV Limited | London | 2015 |
| Ecostor 1 Immingham Ltd | London | 2017 |
| Ecostor Grain West Limited | London | 2024 |
| Ecostor Kilbagie Ltd | London | 2024 |
| Ecosun Installation Ltd | Croydon | 2025 |
| Ecotec Electrical Services Limited | Worksop | 2018 |
| Ecotec GAS & Heating Ltd | London | 2026 |
| Ecotech Supplies Limited | Stockport | 2008 |
| Ecotech Wind Park Limited | Stroud | 1998 |
| Ecothermsolutions Ltd | Brentwood | 2025 |
| Ecotricity (Alveston Storage) Limited | Stroud | 2018 |
| Ecotricity (Alveston) Limited | Stroud | 2018 |
| Ecotricity (Bulkworthy Solar) Limited | Stroud | 2018 |
| Ecotricity (Butts Field) Limited | Stroud | 2018 |
| Ecotricity (Cooles Farm Solar) Limited | Stroud | 2021 |
| Ecotricity (Dalby Solar) Limited | Stroud | 2018 |
| Ecotricity (Heck FEN Solar) Limited | Stroud | 2021 |
| Ecotricity (Leechpool) Limited | Stroud | 2019 |
| Ecotricity (Lodge Farm Solar) Limited | Stroud | 2019 |
| Ecotricity (Smart Grid) Limited | Stroud | 2018 |
| Ecotricity Battery Storage Limited | Stroud | 2019 |
| Ecotricity BIZ Limited | Stroud | 2021 |
| Ecotricity Limited | Stroud | 1995 |
| Ecotricity Solar (Borrower) Limited | Stroud | 2020 |
| Ecotricity Solar (Holdco) Limited | Stroud | 2020 |
| Ecotricity Trading Limited | Stroud | 2021 |
| Ecovia Energy Developments Ltd | Huddersfield | 2025 |
| Ecovia Energy Solutions Ltd | Huddersfield | 2025 |
| Ecovicha Ltd | London | 2023 |
| Ecovision Asset Management Limited | Gloucester | 2013 |
| Ecowise Solutions Ltd | Northampton | 2024 |
| Ecpuk Limited | Bolton | 2017 |
| Edana Heating Ltd | Dumbarton | 2019 |
| Eday Renewable Energy Limited | Eday | 2009 |
| Eddie Martin Limited | Gravesend | 2014 |
| Eden AB Solar Limited | Marlborough | 2021 |
| Eden Acquisitions Limited | Norwich | 2020 |
| Eden AW Solar Limited | Marlborough | 2021 |
| Eden BD Solar Limited | Marlborough | 2021 |
| Eden Campus Solar 1 Limited | St. Andrews | 2020 |
| Eden CF Solar Limited | Marlborough | 2021 |
| Eden Cooling Limited | London | 2019 |
| Eden CP Bess Limited | Marlborough | 2021 |
| Eden Energy US Consultant Ltd | Glasgow | 2026 |
| Eden Estuary Energy Limited | St. Andrews | 2014 |
| Eden FG Solar Limited | Marlborough | 2019 |
| Eden LD Solar Limited | Marlborough | 2019 |
| Eden Multi-Utilities and Groundwork’S Limited | Carlisle | 2021 |
| Eden RB Solar Limited | Marlborough | 2020 |
| Eden Renewable Energy Ltd | Liverpool | 2021 |
| Eden Solarfair Limited | Radstock | 2011 |
| Eden Sustainable Investments 8 Ltd | Letchworth Garden City | 2018 |
| Eden Sustainable Power Ltd | London | 2025 |
| Eden Utilities Ltd | Henfield | 2011 |
| Eden Ventilation Limited | Leeds | 2011 |
| Edenbane Wind Ltd | Tyrone | 2021 |
| Edenlas Limited | Bridgend | 2022 |
| Edenmore Biogas Limited | Craigavon | 2014 |
| Ederline Hydro Limited | Edinburgh | 2011 |
| EDF Air Conditioning Limited | Dunstable | 2012 |
| EDF Development Company Limited | London | 2007 |
| EDF Energy (Thermal Generation) Limited | London | 2001 |
| EDF Energy Customers Limited | London | 1988 |
| EDF Energy Limited | London | 1989 |
| EDF Energy Nuclear Generation Group Limited | Glasgow | 2004 |
| EDF Energy Nuclear Generation Limited | Gloucester Business Park | 1995 |
| EDF Energy Renewables Limited | Houghton Le Spring, Sunderland | 2007 |
| EDF ER Development Limited | Houghton Le Spring | 2015 |
| EDF Renewables Community Investment Limited | Houghton Le Spring, Sunderland | 2019 |
| EDF Renewables Solar Limited | Sunderland | 2019 |
| Edge Close Green Energy Limited | Buxton | 2016 |